It takes two people to procreate. Fathers, as 50 percent of the equation, therefore have the right to know of a subsequent pregnancy and/or abortion, but they should not have the right to prevent it. Since it is the woman that gives birth, she should have the right to determine whether or not to carry a baby to full term or abort a pregnancy.
Abortion is a legal way to terminate a pregnancy, a Woman's Right to Choose. But what about the woman's "partner in crime?" The male, the sperm donor, the other half of the chromosomes, what about his rights? He should have them, and they should give him a legal leg to stand on. The abortion debate has many layers like an onion, every layer is another tear down the cheek of society.
If the father is active and supportive in the relationship, then yes, i think he deserves to know about the abortion if the mother is pregnant. If he did not know she was carrying, then it is up to her to tell him if she would like to.
However, if the pregnancy is a cause of rape, or the father is abusive, or missing in her life, than he does not have a right to know of the abortion.
At the end of the day, though, it really is the womans choice.